This is an investigation of the effects of chronic moderate undernutrition on the social, emotional, and cognitive development of children. Six- to eight-year-old children identified as having a history of malnutrition (protein-calorie deficiency) are compared with children who have had more nearly adequate diets. The children are from villages that participated in a longitudinal study from which there are extensive data on food intake, health, growth, and earlier cognitive development. The children are all of very similar social and economic backgrounds. Anthropometry and health and nutritional history are used to assess nutritional status. Standard tests and observations in controlled and natural settings are used in investigating cognitive, sensorimotor, and attentional capacities, and social and emotional behavior. Preliminary findings indicate diet calorie intake from birth to 5 years is significantly related to the child's level of social activity. Children identified as passive and withdrawn in social interaction had significantly lower diet calorie intakes than those who were socially active. Analyses are currently being conducted examining relations between several composite variables related to nutritional history (see MH 02138) and indicies of cognitive functioning, sensorimotor abilities, and social interaction characteristics.